Variable multi-stage waveform detector

ABSTRACT

A variable waveform detector may include multiple stages.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is related to and claims the benefit of theearliest available effective filing date(s) from the following listedapplication(s) (the “Related Applications”) (e.g., claims earliestavailable priority dates for other than provisional patent applicationsor claims benefits under 35 USC § 119(e) for provisional patentapplications, for any and all parent, grandparent, great-grandparent,etc. applications of the Related Application(s)).

RELATED APPLICATIONS

For purposes of the USPTO extra-statutory requirements, the presentapplication constitutes a continuation-in-part of U.S. patentapplication Ser. No. 11/314,978, entitled MULTI-STAGE WAVEFORM DETECTOR,naming Roderick A. Hyde, Muriel Y. Ishikawa, Edward K. Y. Jung, NathanP. Myhrvold, Clarence T. Tegreene, and Lowell L. Wood, Jr. as inventors,filed 21 Dec. 2005, which is currently co-pending, or is an applicationof which a currently co-pending application is entitled to the benefitof the filing date.

For purposes of the USPTO extra-statutory requirements, the presentapplication constitutes a continuation-in-part of U.S. patentapplication Ser. No. 11/355,493, entitled VARIABLE METAMATERIALAPPARATUS, naming Roderick A. Hyde; Nathan P. Myhrvold; Clarence T.Tegreene; and Lowell L. Wood, Jr. as inventors, filed 16 Feb. 2006,which is currently co-pending, or is an application of which a currentlyco-pending application is entitled to the benefit of the filing date.The United States Patent Office (USPTO) has published a notice to theeffect that the USPTO's computer programs require that patent applicantsreference both a serial number and indicate whether an application is acontinuation or continuation-in-part. Stephen G. Kunin, Benefit ofPrior-Filed Application, USPTO Official Gazette Mar. 18, 2003, availableat http://www.uspto.gov/web/offices/com/sol/og/2003/week11/patbene.htm.The present applicant entity has provided above a specific reference tothe application(s) from which priority is being claimed as recited bystatute. Applicant entity understands that the statute is unambiguous inits specific reference language and does not require either a serialnumber or any characterization, such as “continuation” or“continuation-in-part,” for claiming priority to U.S. patentapplications. Notwithstanding the foregoing, applicant entityunderstands that the USPTO's computer programs have certain data entryrequirements, and hence applicant entity is designating the presentapplication as a continuation-in-part of its parent applications as setforth above, but expressly points out that such designations are not tobe construed in any way as any type of commentary and/or admission as towhether or not the present application contains any new matter inaddition to the matter of its parent application(s).

All subject matter of the Related Applications and of any and allparent, grandparent, great-grandparent, etc. applications of the RelatedApplications is incorporated herein by reference to the extent suchsubject matter is not inconsistent herewith.

SUMMARY

An embodiment provides a variable system for interacting withelectromagnetic or other energy that includes a first detector assemblyarranged relative to a second detector assembly.

The foregoing summary is illustrative only and is not intended to be inany way limiting. In addition to the illustrative aspects, embodiments,and features described above, further aspects, embodiments, and featureswill become apparent by reference to the drawings and the followingdetailed description.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows a first embodiment of a detector system.

FIG. 2 shows a zone plate.

FIG. 3 shows an embodiment of the detector system.

FIG. 4 shows a diffraction grating.

FIG. 5 shows an embodiment of the detector system.

FIG. 6 shows a split ring resonator and an interferometer.

FIG. 7 shows a first embodiment of a detector system including a stop.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings, which form a part hereof. In the drawings,similar symbols typically identify similar components, unless contextdictates otherwise. The illustrative embodiments described in thedetailed description, drawings, and claims are not meant to be limiting.Other embodiments may be utilized, and other changes may be made,without departing from the spirit or scope of the subject matterpresented here.

In a first embodiment, shown in FIG. 1, a source 100 provides a firstwave 101 to a detector system 112, where the detector system 112includes an array of subassemblies or detectors 104, arranged to form afirst detector assembly 102. The wave 101 may be any kind of wave,including (but not limited to) an electromagnetic, acoustic, mechanical,or particle wave. The detectors 104 may include (but are not limited to)quantum dots, antennae, photo-detectors, resonant structures, or anynumber of devices or structures that can detect or interact with energy.The size, type, number, orientation, separation, homogeneity, and otherfeatures of the detectors 104 may be dependent on the wavelength of theenergy that the array is configured to detect, the size of the source100, the distance between the source 100 and the first detector assembly102, relative orientations, positions, or other relative aspects of thesource 100 and first detector assembly 102, polarization of the wave101, or a variety of other design considerations.

As a portion of the energy in the wave 101 interacts with the firstdetector assembly 102, a second portion of the energy in the wave 101may travel past the first detector assembly 102, and energy may bere-emitted from the first detector assembly 102, as well. The secondportion and the re-emitted energy combine in whole or in part to form asecond wave 105 that travels as indicated in FIG. 1. A second array ofdetectors 108 that forms a second detector assembly 106 is positioned tointercept the second wave 105. The detectors 108 in the second detectorassembly 106 may be any of the kinds of detectors 104 that weredescribed for the first detector assembly 102. While the detectors 108may be substantially identical in type to the detectors 104, they mayalso differ in type, size, density or other aspects from the detectors104.

The number, arrangement, orientation and other aspects of the detectors104, 108 may vary according to design considerations. The assemblies102, 106 may or may not include a substrate, the substrate beingcontiguous or having spacings. In one approach, each detector assembly102, 106 may comprise a single detector having characteristics such asposition, size, shape and orientation selected according to theparticular design. Alternatively, one or more of the detector assemblies102, 106 may be configured with a plurality of detectors 104, 108 havinga density such that the detectors 104, 108 may interact with respectiveportions of the waves 101, 105. While the illustrative arrangements ofthe detectors 104, 108 are presented with relatively simple arrangementsand with a relatively small number of individual detectors 104, 108 forclarity of presentation, the detector assemblies 102, 106 may includemore or fewer detectors 104, 108 and may be arranged in a variety ofconfigurations depending on the particular design of the detector system112. Further, although the illustrative example includes two assemblies102, 106, the principles and structures herein can be adapted fordetector systems 112 that include three or more detector assemblies 102,106.

Responsive to the first wave 101 and the second wave 105, the detectors104, 108 produce respective signals corresponding to the first andsecond waves 101, 105. In one approach, the respective signals travel toa signal processor 110. While the embodiment shows a single signalprocessor 110 that receives signals from detectors 104 and 108, in otherconfigurations each of the signals may travel to a respective processor110 or to more than one processor 110. Moreover, although the signalprocessor 110 is shown as separate from the detectors 104, 108, thesignal processor 110 and one or more of the detectors 104, 108 may bepart of a single assembly. In still another approach, other components,such as amplifiers, filters, wireless couplers, mixers, or othercomponents may be interposed between the detectors 104, 108 and thesignal processor 110 or may be integral to the signal processor 110.Further, in some applications, the signals from the detectors 104, 108may be used directly or supplied to an external system withoutsignificant processing.

Although FIG. 1 is shown with the source 100 providing the first wave101 directly to the first detector assembly 102, in another embodimentthe first wave 101 may not travel directly from the source 100 to thefirst detector assembly 102. For example, the first wave 101 mayencounter a lens, diffractive element, obstruction, hologram, object tobe imaged, or a different object between the source 100 and the firstdetector assembly 102.

The source 100 may, for example, be a laser, an acoustic transducer, anatural source of waves such as solar energy, or a different source ofwaves. The source 100 may be configured to produce coherent orincoherent radiation and may be configured to scan over an energy rangeor to spatially scan over the detector system 112. Further, although theembodiment in FIG. 1 is shown with a single source 100, more than onesource may produce the wave 101, or the source of the wave 101 may beunknown. The wave 101, although shown having a simple curved wavefrontin FIG. 1, may be any shape or form.

In one embodiment, the detectors 104 may be arranged to form the zoneplate 206 shown in FIG. 2. In this case the detectors 104 may bearranged in alternating sections 202, 204 that are substantiallyconcentric as shown in FIG. 2. The zone plate 206 may be included in thefirst detector assembly 102, and the second detector assembly 106 may bepositioned at the focal plane of the zone plate 206 or at a differentlocation relative to the zone plate 206. The focusing of the arrangementmay be dependent on the density of the detectors 104, and in somearrangements, other material may be included in the detector assembly102 to further define the sections 202, 204. Zone plates are describedin F. A. Jenkins and H. E. White, “FUNDAMENTALS OF OPTICS”, FourthEdition, McGraw-Hill, 1976, which is incorporated herein by reference.

In one case the alternating sections 202, 204 may be substantiallyopaque and transparent, respectively, where the detectors 104 areeffectively opaque to the energy incident on them and are positioned toform the sections 202. Examples of such detectors 104 may include, butare not limited to, parabolic reflector antennae or photo-detectors.Although the sections 202, 204 are described in this embodiment as beingopaque or transparent, it may be the case that not every section 202 isopaque and not every section 204 is transparent, or the opaque sections202 may not be entirely opaque and the transparent sections 204 may notbe entirely transparent. One skilled in the art may recognize that anelement having the desired features may still be achieved even if thedesign of the zone plate 206 differs from that described in Jenkins andWhite.

In another case the alternating sections 202, 204 may be phase-shiftingand transparent, respectively, where the detectors 104 may be resonantstructures such that they absorb and re-resonate energy and arepositioned to form the sections 202. Examples of such structures mayinclude some antennae, split ring resonators, quantum dots, or adifferent kind of detector. Although the sections 202, 204 are describedin this embodiment as being phase-shifting or transparent, it may be thecase that not every section 202 is phase-shifting and not every section204 is transparent, or the phase-shifting sections 202 may not beentirely phase-shifting and the transparent sections 204 may not beentirely transparent. Moreover, some of the sections 202, 204 may bepartially transmissive or have some gradation of phase, absorption orgain.

Although the zone plate 206 in FIG. 2 is shown having circular sections202, 204 it is not necessary for a zone plate 206 to have circularsections. For example, a square zone plate is described in F. J.González, J. Alda, B. Ilic, and G. D. Boreman, “INFRARED ANTENNASCOUPLED TO LITHOGRAPHIC FRESNEL ZONE PLATE LENSES”, Applied Optics,Volume 43, Number 33, Nov. 20, 2004, which is incorporated herein byreference, and other geometries may also be implemented as appropriate.

The detectors 104 may be arranged to change the phase of the first wave101 in a spatially varying manner to focus the wave, form an image, orfor another purpose. For example, the detectors 104 may be arrangedanalogously to a Gabor zone plate or a hologram as described in F. L.Pedrotti and L. S. Pedrotti, “INTRODUCTION TO OPTICS”, Second Edition,Prentice-Hall, Inc., 1993, which is incorporated herein by reference.The phase of the wave 101 may be varied by varying the density ofdetectors 104, by varying the properties of the detectors 104, or insome other way.

FIG. 3 shows the detector system 112 where the first detector assembly102 is arranged to form a focusing element, where the focusing elementmay be a zone plate 206. Parallel incoming rays 302 are incident on thefirst detector assembly 102 and are focused to the second detectorassembly 106, where in this embodiment the second detector assembly 106includes a single detector 108. Information from the detectors 104, 108is transmitted to the signal processor 110. FIG. 3 is shown with asingle detector 108 located a focal distance 304 away from the zoneplate 206, however the second detector assembly 106 may comprise morethan one detector 108, and the detector may not be at the focal point ofthe zone plate 206. Further, FIG. 3 is shown with parallel incoming rays302 (where the rays 302 show the direction of propagation of the wave101) incoming at normal incidence to the first detector assembly 102,however the wave 101 need not impinge on the first detector assembly 102at normal incidence as shown in FIG. 3 and the wave 101 need not be asubstantially plane wave.

In another embodiment, the detectors 104 may be arranged as adiffraction grating 402 having alternating sections 404, 406 that aresubstantially parallel, as shown in FIG. 4. The diffraction grating 402may be included in the first detector assembly 102, and the seconddetector assembly 106 may be positioned to receive radiation diffractedby the grating 402. The properties of the grating 402 may be dependenton the width of the sections 404, 406, the number of sections 404, 406,or another parameter. Diffraction gratings are described in Jenkins andWhite.

In one approach the alternating sections 404, 406 may be substantiallyopaque and transparent, respectively, where the detectors 104 areeffectively opaque to the energy incident on them and are positioned toform the sections 404. In another case the alternating sections 404, 406may be phase-shifting and transparent, respectively, where the detectors104 may be resonant structures such that they absorb and re-resonateenergy and are positioned to form the sections 404. In another case,sections 404 and 406 may both include phase-shifting detectors such thatthe detectors 104 in sections 404 and the detectors 104 in sections 406phase shift by different amounts to form a diffraction grating 402. Insome arrangements, other material may be included in the diffractiongrating 402 to further define the sections 404, 406. As described forthe zone plate 206, one skilled in the art may recognize that a selectedoptical or other response features may still be produced even if thedesign of the diffraction grating 402 described in Jenkins and White isnot adhered to exactly.

FIG. 5 shows the detector system 112 where the detectors 104 in thefirst detector assembly 102 are arranged to form a diffraction grating402. Parallel incoming rays 302 are incident on the first detectorassembly 102 and are diffracted to the second detector assembly 106,where the second detector assembly 106 may be positioned to receiveradiation diffracted by the grating 402. The diffraction grating 402 isconfigured to diffract different frequencies of radiation (representedby rays 502, 504, 506, 508) at different angles, and the second detectorassembly 106 may be positioned with one or more detectors 108 positionedto receive energy of a given frequency or range of frequencies.Information from the detectors 104, 108 is transmitted to the signalprocessor 110. FIG. 5 is shown with four detectors 108 approximatelyequally spaced, however the second detector assembly 106 may compriseany number of detectors 108, and the detectors 108 may be located at anyplace on the second detector assembly 106. Further, FIG. 5 is shown withparallel incoming rays 302 (where the rays 302 show the direction ofpropagation of the wave 101) incoming at normal incidence to the firstdetector assembly 102, however the wave 101 need not impinge on thefirst detector assembly 102 at normal incidence as shown in FIG. 5 andthe wave 101 need not be a substantially plane wave.

FIG. 5 shows both detector assemblies 102, 106 connected to the signalprocessor 110, however in some configurations it is not necessary forthe detector assemblies 102, 106 to be connected to the signal processor110. Or, only one of the detector assemblies 102 or 106 may be connectedto the signal processor 110.

The configuration in FIG. 5 may be such that the detector assembly 102is arranged to detect radiation in a range of energies and incomingangles and the detector assembly 106 is configured to detect radiationin a different range of energies and incoming angles, as described forthe configuration in FIG. 3. The detector(s) 108 may be positioned, asshown in FIG. 5, such that each detector 108 receives a different energyband.

Although the embodiments in FIGS. 1, 3, and 5 are described as havingtwo detector assemblies 102, 106, the detector system 112 may includemore than two detector assemblies. In such arrangements, either or bothof the detector assemblies may provide, shape or otherwise influence thefirst and/or second waves to produce additional waves for interactionwith a third detector assembly (not shown). Similarly, as additionaldetector assemblies are included, each may act as both a detectorassembly and as a structure that interacts with energy. Moreover,portions of energy can propagate from the additional detector assembliesin a similar fashion to the second wave.

Further, FIGS. 1, 3, and 5 show the first and second detector assemblies102, 106 being centered about (or substantially centered about) a commonlocation along the y direction 122. However, in some embodiments it maybe desirable for the detector assemblies 102, 106 to be offset from eachother along the y direction 122. Although the detector assemblies 102,106 are shown as being substantially planar, it is not necessary forthem to be planar and they may take any shape.

The signals from the detectors 104, 108 may be delivered to the signalprocessor 110 in a variety of ways. For detectors 104, 108 that generatean electrical signal, such as many kinds of antennae, photodetectors, oracoustic transducers, the signals from the detectors 104, 108 may bedelivered to the signal processor 110 electrically. For detectors 104,108 that receive electromagnetic energy, the signals from the detectors104, 108 may be delivered to the signal processor 110 via a waveguidesuch as an optical fiber, via free space or in a different way. Althoughelectrical and electromagnetic signals are presented as examples offorms that the signal may take, one skilled in the art will recognizethat the type of signal may depend on the type of detector, and mayadjust the signal processor 110 based on the type or types of signalsinput to the signal processor 110. The signals from all of the detectors104, 108 may all be of the same form, for example all electrical signalsor all electromagnetic signals, or different signals from the detectors104, 108 may be delivered to the signal processor 110 in differentforms.

Although the above embodiments are described in terms of having only onekind of detector, it may be desirable in some configurations to includemore than one kind of detector. For example, the first or seconddetector assembly 102, 106 may include antennae of different sizes, orthey may include both antennae and photodetectors. These configurationsare illustrative examples of the different combinations of detectors104, 108 that may be configured, and many other configurations arepossible.

Returning to the illustrative embodiments of FIGS. 1, 3, and 5, thefirst wave 101 is described as impinging on the first detector assembly102 for simplicity of explanation. The first wave 101 is representativeof energy incident on the first detector assembly 102 and is not limitedto monochromatic plane waves, and can include any kind of energydistribution, including those with a range of energies, irregularwavefronts, or distributions where the spatial and frequency range ofthe energy is unknown.

The detectors 104, 108 are configured to receive energy having an energydistribution, the energy distribution including a frequency range. Thisfrequency range may be very small such that the detectors 104, 108 areconsidered to detect substantially one frequency, or the frequencyresponse of the detectors 104, 108 may be a function of frequency. Thedetectors 104, 108 may all detect energy in substantially the samefrequency range, or the detectors 104 in the first detector assembly 102may detect energy in a first frequency range and the detectors 108 inthe second detector assembly 106 may detect energy in a second frequencyrange, or the detector assemblies 102, 106 may include a variety ofdetectors 104, 108 that receive energy in a variety of frequency ranges.

In one embodiment, one or both of the detector assemblies 102, 106 mayinclude a device that receives energy and may guide the energy todetectors 104, 108, such as a concentrator designed to receive solarenergy as described, for example, in U.S. Pat. No. 4,149,902 entitledFLUORESCENT SOLAR ENERGY CONCENTRATOR to Mauer, et al., which isincorporated herein by reference. In one embodiment, the concentratormay be formed in the shape of the zone plate 206 shown in FIG. 2, suchthat the first detector assembly 102 includes the zone plate 206 and thedetectors 104 are configured to receive the energy from theconcentrator, where the zone plate 206 is incorporated into the detectorsystem 112 as described in FIG. 3. Although the embodiment is describedwith the concentrator shaped as a zone plate 206 configured to beincluded in the first detector assembly 102, the concentrator may have adifferent shape, and may be included in the second detector assembly 106or both the first and second detector assemblies 102, 106, wheredetectors 104, 108 may be positioned to receive the energy collected.The device may be a solid planar device or may be shaped to focus ordirect energy. Further, although a device that receives and guides solarenergy is described, one skilled in the art may extend the concept todifferent frequency ranges or different kinds of energy.

In one embodiment the first or second detector assemblies 102, 106 mayinclude a metamaterial. Examples of metamaterials can be found in R. A.Shelby, D. R. Smith, and S. Schultz, “EXPERIMENTAL VERIFICATION OF ANEGATIVE INDEX OF REFRACTION”, Science, Volume 292, Apr. 6, 2001; D. R.Smith, W. J. Padilla, D. C. Vier, S. C. Nemat-Nasser, and S. Schultz,“COMPOSITE MEDIUM WITH SIMULTANEOUSLY NEGATIVE PERMEABILITY ANDPERMITTIVITY”, Physical Review Letters, Volume 84, Number 18, May 1,2000; D. R. Smith, J. B. Pendry, M. C. K. Wiltshire, “METAMATERIALS ANDNEGATIVE REFRACTIVE INDEX”, Science, Volume 305, Aug. 6, 2004; D. R.Smith and D. C. Vier, “DESIGN OF METAMATERIALS WITH NEGATIVE REFRACTIVEINDEX”, Proceedings of SPIE, Volume 5359, Quantum Sensing andNanophotonic Devices, Manijeh Razeghi, Gail J. Brown, Editors, July2004, pp. 52-63; each of which is incorporated herein by reference.Although the above references describe metamaterials having negativeindex of refraction, other metamaterials have effective refractiveindices that are positive, negative or some combination thereof.

One example of a metamaterial, described in D. R. Smith, W. J. Padilla,D. C. Vier, S. C. Nemat-Nasser, and S. Schultz, “COMPOSITE MEDIUM WITHSIMULTANEOUSLY NEGATIVE PERMEABILITY AND PERMITTIVITY”, Physical ReviewLetters, Volume 84, Number 18, May 1, 2000, includes an array of splitring resonators and wires. In this case, the array may be configured toform the first detector assembly 102, where the individual split ringresonators and wires form the detectors 104. In one embodiment, themetamaterial may be arranged to have a gradient index of refraction asdescribed in D. R. Smith, J. J. Mock, A. F. Starr, and D. Schurig, “AGRADIENT INDEX METAMATERIAL”, available at:http://arxiv.org/abs/physics/0407063; and R. B. Greegor, C. G.Parazzoli, J. A. Nielsen, M. A. Thompson, M. H. Tanielian, and D. R.Smith, “SIMULATION AND TESTING OF A GRADED NEGATIVE INDEX OF REFRACTIONLENS,” Applied Physics Letters, Volume 87, page 091114, Aug. 29, 2005,each of which is incorporated herein by reference.

The embodiment in FIG. 6 demonstrates one way of extracting a signalfrom an array including a split ring resonator. FIG. 6 shows a splitring resonator 602 proximate to an optical interferometer 604, where theinterferometer 604 includes an electrooptic polymer. The interferometer604 is similar to a Mach-Zehnder interferometer, described in Jenkinsand White. The interferometer 604 is configured with an input end 608,an output end 610, and two straight sections 606, 607. One or both ofthe straight sections 606, 607 includes or is substantially adjacent toa region having an electrooptic polymer. The interferometer 604 isconfigured to receive electromagnetic energy, such as light energy, atthe input end 608, and guide the electromagnetic energy. Theelectromagnetic energy divides, typically into two substantially equalportions at the first branch 609. A first portion travels through one ofthe straight sections 606 and the other through the other straightsection 607.

The energy from the straight sections 606, 607 recombines at the secondbranch 611, and provides an output signal at the output end 610. Whenthe split ring resonator 602 responds to incoming electromagneticenergy, the resonator produces localized fields, due to induced currentsand/or electrical potentials in the resonator 602. The localized fieldsinteract with the electrooptic polymer and produce variations in theeffective refractive index experienced by the guided energy. This thenchanges the effective path length of the arm(s) 606, 607 of theinterferometer 604 that include the electrooptic polymer. As is knownfor interferometric modulators and switches, the amount of light exitingthe output end is a function of the relative change in effectiverefractive index in the legs of the interferometer, thus providinginformation about the current in the split ring resonator 602. Onestraight section 606 or 607 of the interferometer 604 may partially orentirely comprise an electrooptic polymer, both straight sections 606,607 may comprise electrooptic polymer, or the entire interferometer 604may comprise electrooptic polymer. The interferometer 604 may includewaveguiding portions that are defects etched in a material, portionsincluding waveguiding dielectric, portions that allow electromagneticenergy to propagate in free space, or other configurations. Moreover,the position of the interferometer 604 relative to the split ringresonator 602 is one illustrative example and the relative positions maybe different from that shown in FIG. 6 and may still provide a signalresponsive to current in the split ring resonator 602. Further, althoughthe split ring resonator 602 in FIG. 6 is shown having substantiallyrectilinear geometry, this is not required and other split ringresonator geometries are known to those skilled in the art. Further,although the illustrative embodiment presents one interferometricapproach, other approaches to detecting electromagnetic energy in theresonators may use interferometric or non-interferometric approaches.For example, L. Dalton, “Integrated Optics/Electronics UsingElectro-Optic Polymers”, Mat. Res. Soc. Symp. Proc., 2004, Volume 817,Pages L7.2.1-L7.2.12, shows one approach to detecting fields usingelectrooptic polymers. Similarly, structures can utilize frequencyshifting induced by fields, such as is described in A. Driessen et al.,“Microresonators as promising building blocks for VLSI photonics”,Proceedings of SPIE, Integrated Optics: Theory and Applications, 2005,Volume 5956, Pages 59560Q-1-59560Q-14.

Another way of extracting signals from a metamaterial array is byincluding one or more antennae in the array. Measurements of the fieldsinside a metamaterial comprising split ring resonators and wires using ascannable antenna are described in J. B. Brock, A. A. Houck, and I. L.Chuang, “FOCUSING INSIDE NEGATIVE INDEX MATERIALS”, Applied PhysicsLetters, Volume 85, Number 13, Sep. 27, 2004, which is incorporatedherein by reference. Although an antenna is one way of extracting thesignal from the metamaterial, the signals may be extracted in otherapproaches. For example, the signal may be sampled using one or moreswitched circuits coupled to the resonators. In still another example,the signal may be measured by directly or indirectly measuring thecurrent in the split ring resonators or wires or other properties of thesplit ring resonators or wires.

Moreover, although the illustrative example of a metamaterial includedsplit ring resonators, other types of materials or metamaterials may beincorporated into one or more of the detector assemblies or in additionto the detector assemblies. The selection of the structure of themetamaterial, its properties, such as its effective permittivity,permeability, principal frequency, loss, gain or other aspect is adesign choice that may depend upon the intended application, costconstraints, expected input or other design constraints. Similar designconsiderations apply to the methods and structures for determining theproperties of the energy intercepted by the detector assemblies.Further, the field of metamaterials and negative index materials isevolving rapidly and other approaches to forming such materials havebeen described, including those incorporating transmission lines orwires, nanorods, multiferroic materials, or other approaches toestablishing an effective permittivity and/or permeability. In someapplications these approaches may be incorporated into one or more ofthe detector assemblies 102, 106. Although metamaterials have beendescribed as related to electromagnetic radiation, such materials orequivalents to such materials may be implemented for other types ofwaves. For example, phononic metamaterials have been reported in SuxiaYang, J. H. Page, Zhengyou Liu, M. L. Cowan, C. T. Chan, and Ping Sheng,“FOCUSING OF SOUND IN A 3D PHONONIC CRYSTAL”, Physical Review Letters,Volume 93, Page 024301, Jul. 7, 2004, which is incorporated herein byreference.

In one embodiment, the detectors 104, 108 may be quantum dots. Oneexample of how quantum dots may be incorporated as a detector isdescribed in J. L. Jimenez, L. R. C. Fonseca, D. J. Brady, J. P.Leburton, D. E. Wohlert, and K. Y. Cheng, “THE QUANTUM DOTSPECTROMETER”, Applied Physics Letters, Volume 71, Number 24, Dec. 15,1997, page 3558-3560, which is incorporated herein by reference. Thequantum dots may be incorporated as detectors 104, 108 in either thefirst detector assembly 102, the second detector assembly 106, or both.An assembly of quantum dots may comprise a single type of quantum dotthat absorbs and re-emits in a relatively narrow wavelength band, or itmay comprise more than one type of quantum dot, thus expanding thewavelength band at which the detector assemblies absorb and re-emit.

In another embodiment the detectors 104, 108 may be antennae, where theantennae may include dipole or other types of antennae. Those skilled inthe art may recognize that a multitude of different devices may form anantenna and that an antenna may exist in a wide variety of shapes andsizes. For example, an antenna may be very small and include a nanotube,as is described in Y. Wang, K. Kempa, B. Kimball, J. B. Carlson, G.Benham, W. Z. Li, T. Kempa, J. Rybczynski, A. Herczynski, Z. F. Ren,“RECEIVING AND TRANSMITTING LIGHT-LIKE RADIO WAVES: ANTENNA EFFECT INARRAYS OF ALIGNED CARBON NANOTUBES”, Applied Physics Letters, Volume 85,Number 13, Sep. 27, 2004, which is incorporated herein by reference. Theantennae may be incorporated as detectors 104, 108 in one or more of thefirst detector assembly 102 and the second detector assembly 106. Anassembly of antennae may comprise a single type of antenna that absorbsand re-emits in a relatively narrow wavelength band, or it may comprisemore than one type of antenna, thus expanding the wavelength band atwhich the detector assemblies absorb and re-emit.

The signal processor 110 may perform a variety of functions. In oneexample, where the detectors 104 in the first array are antennae, theprocessor 110 may extract information from the respective signals fromthe first detector assembly 102 according to conventional antenna arraytechniques. Where the detectors 108 in the second array are antennae,the processor 110 may also extract information from the respectivesignals from the second detector assembly 106 according to conventionalantenna array techniques. Alternatively, where the second detectorassembly 106 includes a single antenna, the processor 110 may extractinformation from the respective signal from the single antenna accordingto conventional transceiver techniques.

While these illustrative examples involve one or more antenna arrays andapplication of antenna array or transceiver techniques, the signalprocessor 110 may apply a range of other techniques in addition to or asan alternative to the previously described techniques. For example, thesignal processor 110 may perform a Fourier transform on one or more ofthe signals for imaging or other purposes, a correlation orautocorrelation between signals, or it may include a filter, which maybe a noise filter or other type of filter, and may be low pass, highpass, or bandpass. In one embodiment the source 100 and the detectorsystem 112 may be in motion relative to one another and the signalprocessor 110 may be configured to compensate for this relative motion.

In one embodiment the signal processor 110 may be configured to sampledata from the detectors 104, 108 as a function of time. Such aconfiguration may be desirable especially in systems where the source100 and detector system 112 are in motion relative to each other. Inthis case the sampling rate may be adjustable, and may be determined bythe magnitude of the relative motion between the source 100 and thedetector system 112.

In one embodiment the signal processor 110 may comprise a computer,wherein the respective signals generated by the first detector assembly102 or the second detector assembly 106 or a signal corresponding to therespective signals from the first or second detector assemblies 102, 106is guided to the computer. The computer may comprise software forprocessing the signals received and it may include one or more devices(not shown) for interfacing the computer and the detector assemblies102, 106. The computer may or may not be proximate to the first andsecond detector assemblies 102, 106.

In one embodiment, the signal processor 110 may include components forprocessing electromagnetic signals. In this case, the signal processor110 may include components for mixing, reflecting, focusing, orotherwise changing the path of electromagnetic radiation. One example ofsuch a signal processor 110 is an arrangement for heterodyning twosignals, in which case the signal processor 110 may include a nonlineardevice such as a vacuum tube, transistor, or diode mixer.

Applications of the embodiments described in FIGS. 1-6 are wide rangingand may include imaging and/or image processing, x-rayspectrometry/spectroscopy, radar, medical imaging applications such asPET, CAT scans, MRI, and ultrasound, LIDAR, and other applications.

In one embodiment the subassemblies 104 may be adjustable. Thesubassemblies 104 may be arranged in a first spatial distribution thatis variably responsive, and may be temporally variable. The firstspatial distribution may form a portion of a first pattern such that thefirst pattern is variably responsive, where the first pattern may betemporally variable, and where the first pattern may be variablyresponsive as a function of the first energy distribution.

In one embodiment at least one of the plurality of subassemblies 104 mayinclude a MEMS device, where the MEMS device may be configured tofacilitate adjustment of the one or more subassemblies 104. Although aMEMS device is provided as one exemplary embodiment of a way to adjustthe subassemblies 104, other ways of changing the position of elementsexist and one skilled in the art may provide other means for adjustment.Further, although a MEMS device may adjust subassemblies 104 having, forexample, micron-scale dimensions, in some embodiments the subassemblies104 may have different dimensions and/or different devices providingadjustment.

In another embodiment at least one of the plurality of adjustablesubassemblies is switchable as described, for example, in U.S. patentapplication Ser. No. 11/355,493, entitled VARIABLE METAMATERIALAPPARATUS, naming Roderick A. Hyde; Nathan P. Myhrvold; Clarence T.Tegreene; and Lowell L. Wood, Jr. as inventors, filed 16 Feb., 2006,which is incorporated herein by reference. For example, depending on thetype of subassembly 104, they may be switched on and off, theirproperties such as dielectric constants may be varied by applying avoltage to them or in another way, and there are many other ways ofswitching subassemblies 104 depending on the type of subassembly 104.

In one embodiment the first pattern forms a focusing elementcharacterized by a focal distance 304 that is a function of the firstenergy distribution, such as the zone plate 206 shown in FIG. 2. Asdescribed with respect to FIG. 2, the focusing of the arrangement may bedependent on the density of the detectors 104, and in some arrangements,other material may be included in the detector assembly 102 to furtherdefine the sections 202, 204. In the case where the first pattern isvariable, the pattern may vary to change the effective size of thesections 202, 204, by varying the detectors 104, varying other materialthat is included in the detector assembly 102, or both. The detectors104 and/or the other material may be varied by moving them, by changingtheir properties, by switching them, and/or by other means. In this casethe first detector assembly 102 and the second detector assembly 106 maybe separated by a separation distance that is variable as a function ofthe focal distance 304, where the separation between the first detectorassembly 102 and the second detector assembly 106 may be configured tovary.

Although the first pattern is described above as forming a zone plate206, this is just one exemplary embodiment of the first pattern, andthere are many other types of elements that may be formed. For example,other diffractive elements exist, such as gratings. Further, the firstpattern may form a three-dimensional structure, an array with irregularspacings, or a different pattern.

In one embodiment a first subassembly 104 has a first variable responsefunction and/or a first variable dimension, which may include a firstcentral frequency and/or a first linewidth. Elements having variableresponse functions and variable dimensions, and methods for varying themare described in VARIABLE METAMATERIAL APPARATUS, previouslyincorporated by reference.

In one embodiment a first subassembly 104 has a first orientation,wherein the first orientation is variably responsive. In this case thefirst subassembly 104 may include a MEMS device configured to facilitatethe change of the orientation of the first subassembly 104, or theorientation of the subassembly 104 may be varied in a different way. Thesubassemblies 104 in the first detector array 102 may be configured tobe individually variable such that each subassembly 104 may have adifferent orientation, or the subassemblies 104 in the first detectorarray 102 may all have the same orientation, where the orientation isadjustable. Further, the subassemblies 104 may be configured such thatboth their position and orientation are variably responsive, such thatthe subassembly 104 may be moved and/or rotated. There are manydifferent ways of varying the subassemblies 104 relative to one anotherand/or relative to a different reference, and one skilled in the art mayfind different ways and/or combinations of ways of varying thesubassemblies 104.

The apparatus may include a signal processor 110 or other electroniccircuitry, where the signal processor 110 may be operably connected toat least one of the plurality of subassemblies 104, to receive a signalfrom the at least one of the plurality of subassemblies 104 and/or tosend a signal to the at least one of the plurality of subassemblies 104.The signal processor 110 may be operably connected to the seconddetector assembly 106, to receive a signal from the second detectorassembly 106 and/or to send a signal to the second detector assembly106. The signal processor 110 may be configured to change thesubassemblies 104 in ways described above, for example, to change theirrelative positions and/or orientations, to switch them, to change theirresponse functions, and/or to change them in another way. The signalprocessor 110 may further be configured to change the subassemblies 108in the second detector assembly 106 in any of the ways described for thesubassemblies 104 in the first detector array. Further, the signalprocessor 110 may be configured to change some of the subassemblies 104,108 in response to others of the subassemblies 104, 108, and/or thesignal processor 110 may be configured to change other properties of thedetector system 112, such as the separation 114 between detectorassemblies, based on information received from the subassemblies 104,108. There are many ways of modifying the detector system 112 based onfeedback obtained from the subassemblies 104, 108, and one skilled inthe art may find many applications of varying the detector system 112based on feedback from the subassemblies 104, 108.

In some embodiments the detector system 112 may include more elementsthan are shown in FIGS. 1-7. For example, the detector system mayinclude more than two detector assemblies 102, 106. Further, thedetector system may include other elements including, but not limitedto, filters, polarizers, multiple signal processors, and amplifiers.

Applications of the apparatus described above are wide ranging. Forexample, the first and/or second detector assemblies 102, 106 may beconfigured to receive information about the energy distribution of thefirst wave 101, send this information to the signal processor 110, wherethe signal processor 101 then adjusts parameters of the detector systemaccordingly, such as the distribution, position, and/or orientation ofthe subassemblies in the first or second detector assemblies 102, 106,the separation between the first or second detector assemblies 102, 106,or other parameters.

In another embodiment, the signal processor 110 is configured to performcontrast comparisons between adjacent subassemblies 104 and/or 108 toadjust the position of the subassemblies for optimal imaging,auto-focusing, or for other applications. In still another embodiment,the signal processor 110 is configured to adjust the first and seconddetector assemblies 102, 106 for spectroscopic imaging, such that thefirst detector assembly 102 forms a zone plate 206 having a focaldistance 304 that is a function of the energy of the first wave 101, andwhere the separation between the first and second detector assemblies102, 106 varies (for example, as a function of time) to obtain images atdifferent energies. In another embodiment, the first and/or seconddetector assemblies 102, 106 include subassemblies 104 and/or 108responsive to different energies, such that subassemblies 104 and/or 108having different energy responses may be switched and/or moved as afunction of time, for imaging, spectroscopy, or for other purposes.

In one embodiment, adjusting a first detector assembly 102 defines aredistribution pattern that redistributes a waveform (or the first wave101). The redistributed waveform (or the second wave 105) may bedetected at one or more locations defined by the selected redistributionpattern. The first detector assembly 102 may be adjusted by changing arelative position of the first detector assembly 102, with respect to asecond detector assembly 106 or another reference.

The energy distribution of the waveform 101 may be measured and therelative position and/or relative orientation of the first detectorassembly 102 may be changed accordingly, or the first detector assembly102 may be switched according to the energy distribution.

The redistributed waveform 105 may be detected with a second detectorassembly 106, where the second detector assembly 106 may be adjusted. Inone embodiment the second detector assembly 106 is adjusted according tothe redistributed waveform 105. Adjusting the second detector assembly106 may include changing its relative orientation and/or distribution.

In one embodiment shown in FIG. 7 the redistributed waveform 105 islimited with a stop 702 having a stop aperture 704. The stop may be afixed component or variable component. In some approaches, the stopaperture 704 may be changed independently of other adjustments, or maybe adjusted in conjunction with other adjustments to form a compositeadjustment.

In one embodiment the first detector assembly 102 includes an array ofsubassemblies 104 having a distribution, where adjusting the firstdetector assembly 102 may include changing the distribution ofsubassemblies 104, or where adjusting the first detector assembly 102may include changing a relative orientation of at least one subassembly104 in the array of subassemblies 104.

In one embodiment the first detector assembly 102 is configured to senda signal to a processor 110, and/or the second detector 106 isconfigured to send a signal to the processor 110.

In one embodiment a system for detecting a waveform comprises amultistage detector (or detector system 112) and a controller (or signalprocessor 110) operably connected to change the multistage detector 112,wherein the multistage detector 112 includes a first detector array (orfirst detector assembly 102) arranged to receive a first portion ofenergy from an incoming wave (or first wave 101) and form a secondarywaveform (or second wave 105), and a second detector array (or seconddetector assembly 106) arranged to receive the secondary waveform 105.The first detector array 102 may have a first spatial distribution,where the controller 110 is operably connected to change the firstspatial distribution. The second detector array 106 may have a secondspatial distribution, where the controller 110 is operably connected tochange the second spatial distribution. The first detector array 102 andthe second detector array 106 may have a separation 114, wherein thecontroller 110 is operably connected to change the separation 114. Inone embodiment, the system may include a third detector array, notshown. The controller 110 may be operably connected to receive a signalfrom the first detector array 102, or from the second detector array106.

Those having skill in the art will recognize that the state of the arthas progressed to the point where there is little distinction leftbetween hardware and software implementations of aspects of systems; theuse of hardware or software is generally (but not always, in that incertain contexts the choice between hardware and software can becomesignificant) a design choice representing cost vs. efficiency tradeoffs.Those having skill in the art will appreciate that there are variousvehicles by which processes and/or systems and/or other technologiesdescribed herein can be effected (e.g., hardware, software, and/orfirmware), and that the preferred vehicle will vary with the context inwhich the processes and/or systems and/or other technologies aredeployed. For example, if an implementer determines that speed andaccuracy are paramount, the implementer may opt for a mainly hardwareand/or firmware vehicle; alternatively, if flexibility is paramount, theimplementer may opt for a mainly software implementation; or, yet againalternatively, the implementer may opt for some combination of hardware,software, and/or firmware. Hence, there are several possible vehicles bywhich the processes and/or devices and/or other technologies describedherein may be effected, none of which is inherently superior to theother in that any vehicle to be utilized is a choice dependent upon thecontext in which the vehicle will be deployed and the specific concerns(e.g., speed, flexibility, or predictability) of the implementer, any ofwhich may vary. Those skilled in the art will recognize that opticalaspects of implementations will typically employ optically-orientedhardware, software, and or firmware.

The foregoing detailed description has set forth various embodiments ofthe devices and/or processes via the use of block diagrams, diagrammaticrepresentations, flowcharts, and/or examples. Insofar as such blockdiagrams, diagrammatic representations, flowcharts, and/or examplescontain one or more functions and/or operations, it will be understoodby those within the art that each function and/or operation within suchblock diagrams, diagrammatic representations, flowcharts, or examplescan be implemented, individually and/or collectively, by a wide range ofhardware, materials, components, software, firmware, or virtually anycombination thereof. In one embodiment, several portions of the subjectmatter described herein may be implemented via Application SpecificIntegrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs),digital signal processors (DSPs), or other integrated formats. However,those skilled in the art will recognize that some aspects of theembodiments disclosed herein, in whole or in part, can be equivalentlyimplemented in integrated circuits, as one or more computer programsrunning on one or more computers (e.g., as one or more programs runningon one or more computer systems), as one or more programs running on oneor more processors (e.g., as one or more programs running on one or moremicroprocessors), as firmware, or as virtually any combination thereof,and that designing the circuitry and/or writing the code for thesoftware and or firmware would be well within the skill of one of skillin the art in light of this disclosure. In addition, those skilled inthe art will appreciate that the mechanisms of the subject matterdescribed herein are capable of being distributed as a program productin a variety of forms, and that an illustrative embodiment of thesubject matter described herein applies regardless of the particulartype of signal bearing medium used to actually carry out thedistribution. Examples of a signal bearing medium include, but are notlimited to, the following: a recordable type medium such as a floppydisk, a hard disk drive, a Compact Disc (CD), a Digital Video Disk(DVD), a digital tape, a computer memory, etc.; and a transmission typemedium such as a digital and/or an analog communication medium (e.g., afiber optic cable, a waveguide, a wired communications link, a wirelesscommunication link, etc.).

In a general sense, those skilled in the art will recognize that thevarious aspects described herein which can be implemented, individuallyand/or collectively, by a wide range of hardware, software, firmware, orany combination thereof can be viewed as being composed of various typesof “electrical circuitry.” Consequently, as used herein “electricalcircuitry” includes, but is not limited to, electrical circuitry havingat least one discrete electrical circuit, electrical circuitry having atleast one integrated circuit, electrical circuitry having at least oneapplication specific integrated circuit, electrical circuitry forming ageneral purpose computing device configured by a computer program (e.g.,a general purpose computer configured by a computer program which atleast partially carries out processes and/or devices described herein,or a microprocessor configured by a computer program which at leastpartially carries out processes and/or devices described herein),electrical circuitry forming a memory device (e.g., forms of randomaccess memory), and/or electrical circuitry forming a communicationsdevice (e.g., a modem, communications switch, or optical-electricalequipment). Those having skill in the art will recognize that thesubject matter described herein may be implemented in an analog ordigital fashion or some combination thereof.

Those skilled in the art will recognize that it is common within the artto describe devices and/or processes in the fashion set forth herein,and thereafter use engineering practices to integrate such describeddevices and/or processes into image processing systems. That is, atleast a portion of the devices and/or processes described herein can beintegrated into an image processing system via a reasonable amount ofexperimentation. Those having skill in the art will recognize that atypical image processing system generally includes one or more of asystem unit housing, a video display device, a memory such as volatileand non-volatile memory, processors such as microprocessors and digitalsignal processors, computational entities such as operating systems,drivers, and applications programs, one or more interaction devices,such as a touch pad or screen, control systems including feedback loopsand control motors (e.g., feedback for sensing lens position and/orvelocity; control motors for moving/distorting lenses to give desiredfocuses. A typical image processing system may be implemented utilizingany suitable commercially available components, such as those typicallyfound in digital still systems and/or digital motion systems.

Those having skill in the art will recognize that a system may includeone or more of a system housing or support, and may include electricalcomponents, alignment features, one or more interaction devices, such asa touch pad or screen, control systems including feedback loops andcontrol motors (e.g., feedback for sensing lens position and/orvelocity; control motors for moving/distorting lenses to give desiredfocuses). Such systems may include image processing systems, imagecapture systems, photolithographic systems, scanning systems, or othersystems employing focusing or refracting elements or processes.

While particular embodiments of the present invention have been shownand described, it will be understood by those skilled in the art that,based upon the teachings herein, changes and modifications may be madewithout departing from this invention and its broader aspects and,therefore, the appended claims are to encompass within their scope allsuch changes and modifications as are within the true spirit and scopeof this invention. Furthermore, it is to be understood that theinvention is solely defined by the appended claims. It will beunderstood by those within the art that, in general, terms used herein,and especially in the appended claims (e.g., bodies of the appendedclaims) are generally intended as “open” terms (e.g., the term“including” should be interpreted as “including but not limited to,” theterm “having” should be interpreted as “having at least,” the term“includes” should be interpreted as “includes but is not limited to,”“comprise” and variations thereof, such as, “comprises” and “comprising”are to be construed in an open, inclusive sense, that is as “including,but not limited to,” etc.). It will be further understood by thosewithin the art that if a specific number of an introduced claimrecitation is intended, such an intent will be explicitly recited in theclaim, and in the absence of such recitation no such intent is present.For example, as an aid to understanding, the following appended claimsmay contain usage of the introductory phrases “at least one” and “one ormore” to introduce claim recitations. However, the use of such phrasesshould not be construed to imply that the introduction of a claimrecitation by the indefinite articles “a” or “an” limits any particularclaim containing such introduced claim recitation to inventionscontaining only one such recitation, even when the same claim includesthe introductory phrases “one or more” or “at least one” and indefinitearticles such as “a” or “an” (e.g., “a” and/or “an” should typically beinterpreted to mean “at least one” or “one or more”); the same holdstrue for the use of definite articles used to introduce claimrecitations. In addition, even if a specific number of an introducedclaim recitation is explicitly recited, those skilled in the art willrecognize that such recitation should typically be interpreted to meanat least the recited number (e.g., the bare recitation of “tworecitations,” without other modifiers, typically means at least tworecitations, or two or more recitations).

1. A method comprising: detecting a waveform with a first detectorassembly; distributing the waveform with the first detector assembly;detecting the distributed waveform at one or more locations with asecond detector assembly; and defining a redistribution pattern byadjusting the first detector assembly responsive to the detecting thedistributed waveform with the second detector assembly.
 2. The method ofclaim 1 further comprising adjusting the second detector assembly. 3.The method of claim 2 further comprising adjusting the second detectorassembly according to the distributed waveform.
 4. The method of claim 2wherein adjusting the second detector assembly includes changing arelative orientation of the second detector assembly.
 5. The method ofclaim 2 wherein adjusting the second detector assembly includes changinga distribution of the second detector assembly.
 6. The method of claim 2wherein adjusting the second detector assembly includes changing arelative position of the second detector assembly.
 7. The method ofclaim 2 wherein adjusting the second detector assembly includesswitching the second detector assembly.
 8. The method of claim 2 whereinadjusting the second detector assembly includes reconfiguring the seconddetector assembly.
 9. The method of claim 1 further comprising sending asignal from the second detector assembly to a processor.